NUMERICAL AND EXPERIMENTAL STUDY OF TURBULENT FREE SURFACE FLOW FOR A FAST SHIP MODEL

Abstract

In this study the experimental and computational results for a fast ship model is presented. The Reynolds Averaged Navier Stokes (RANS) equations and the nonlinear free surface boundary conditions are discretized by means of an overset grid finite volume scheme. The experiments are performed at Istanbul Technical University Towing Tank basin. In the numerical turbulent flow calculations, the relationship between the Boussinesq's hypothesis of turbulence viscosity and the velocities are obtained through the standard k-epsilon turbulence model. Simulations of turbulent free surface flows around the model are performed by using Star CCM+ solver and Volume of Fluid (VOF) model to capture the free surface between air and water. The total resistance of the ship model is compared with the experimental results. Bow and aft wave form developments are also investigated qualitatively. For Froude (Fn) numbers less than 0.25, the computations are found to be well satisfactory, giving efficient and accurate tool to predict curves of resistance. For relatively higher speeds (Fn>0.25) a low Reynolds number turbulence model may be more suitable to predict the resistance.